diff --git a/lib/py/setup.py b/lib/py/setup.py
index 8b1a7beee1..ca77ec08ad 100644
--- a/lib/py/setup.py
+++ b/lib/py/setup.py
@@ -144,10 +144,7 @@ def run_setup(with_binary):
 
 
 try:
-    with_binary = True
-    run_setup(with_binary)
-    sys.exit(0)
-
+    run_setup(with_binary=True)
 except BuildFailed:
     print()
     print('*' * 80)
@@ -155,17 +152,6 @@ def run_setup(with_binary):
     print("Attempting to build without the extension now")
     print('*' * 80)
     print()
-
-# Retry but without the binary
-try:
-    run_setup(False)
-    sys.exit(0)
-
-except BuildFailed:
-    print()
-    print('*' * 80)
-    print("An error occurred while trying to compile without the C extension enabled")
-    print("Build failed")
-    print('*' * 80)
-    print()
-    sys.exit(1)
+    # Fall back to the pure-Python build. If this also fails, let the
+    # exception propagate so the build backend reports the real error.
+    run_setup(with_binary=False)